12,167 research outputs found

    Destination Management through Organizational Ambidexterity

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    Tourism can help regenerate post-colonial, post-conflict and post-disaster destinations (PCCDs), and national governments and destination marketing organisations (DMOs) play a central role in this. They face the dilemma of either consolidating tourism situations with seemingly safe, known, predictable steps, or taking more ambitious risk-prone, less tried-and-tested and more uncertain approaches. This choice can be portrayed as the respective exploitative and explorative dimensions of strategic conceptual framework of organisational ambidexterity (OA). This regional spotlight provides a conceptual analysis using the lens of OA to examine these dynamics. It focuses on the specific case of Haiti, set within the context of the Caribbean region. A range of OA effects in relation to tourist enclaves is identified. In particular, the spotlight argues for less segregation and separation between tourist and local populations, along with a need for DMOs to espouse more exploitative-explorative postures. In terms of wider implications, it can be argued that other Caribbean economies might learn lessons from the discussion of the Haitian case

    Vaccinia Virus Protein C6 Inhibits Type I IFN Signalling in the Nucleus and Binds to the Transactivation Domain of STAT2.

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    The type I interferon (IFN) response is a crucial innate immune signalling pathway required for defense against viral infection. Accordingly, the great majority of mammalian viruses possess means to inhibit this important host immune response. Here we show that vaccinia virus (VACV) strain Western Reserve protein C6, is a dual function protein that inhibits the cellular response to type I IFNs in addition to its published function as an inhibitor of IRF-3 activation, thereby restricting type I IFN production from infected cells. Ectopic expression of C6 inhibits the induction of interferon stimulated genes (ISGs) in response to IFNα treatment at both the mRNA and protein level. C6 inhibits the IFNα-induced Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathway at a late stage, downstream of STAT1 and STAT2 phosphorylation, nuclear translocation and binding of the interferon stimulated gene factor 3 (ISGF3) complex to the interferon stimulated response element (ISRE). Mechanistically, C6 associates with the transactivation domain of STAT2 and this might explain how C6 inhibits the type I IFN signalling very late in the pathway. During virus infection C6 reduces ISRE-dependent gene expression despite the presence of the viral protein phosphatase VH1 that dephosphorylates STAT1 and STAT2. The ability of a cytoplasmic replicating virus to dampen the immune response within the nucleus, and the ability of viral immunomodulators such as C6 to inhibit multiple stages of the innate immune response by distinct mechanisms, emphasizes the intricacies of host-pathogen interactions and viral immune evasion.Wellcome-Trust, Lister Institute of Preventive Medicine U

    Observation of Weak Collapse in a Bose-Einstein Condensate

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    We study the collapse of an attractive atomic Bose-Einstein condensate prepared in the uniform potential of an optical-box trap. We characterize the critical point for collapse and the collapse dynamics, observing universal behavior in agreement with theoretical expectations. Most importantly, we observe a clear experimental signature of the counterintuitive weak collapse, namely, that making the system more unstable can result in a smaller particle loss. We experimentally determine the scaling laws that govern the weak-collapse atom loss, providing a benchmark for the general theories of nonlinear wave phenomena.The GeForce GTX TITAN X used for the numerical simulations was donated by the NVIDIA Corporation. This work was supported by the Royal Society, EPSRC (Grant No. EP/ N011759/1), ERC (QBox), AFOSR, and ARO. A. L. G. and N. N. acknowledge support from Trinity College, Cambridge

    Angular adaptivity with spherical harmonics for Boltzmann transport

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    This paper describes an angular adaptivity algorithm for Boltzmann transport applications which uses Pn and filtered Pn expansions, allowing for different expansion orders across space/energy. Our spatial discretisation is specifically designed to use less memory than competing DG schemes and also gives us direct access to the amount of stabilisation applied at each node. For filtered Pn expansions, we then use our adaptive process in combination with this net amount of stabilisation to compute a spatially dependent filter strength that does not depend on a priori spatial information. This applies heavy filtering only where discontinuities are present, allowing the filtered Pn expansion to retain high-order convergence where possible. Regular and goal-based error metrics are shown and both the adapted Pn and adapted filtered Pn methods show significant reductions in DOFs and runtime. The adapted filtered Pn with our spatially dependent filter shows close to fixed iteration counts and up to high-order is even competitive with P0 discretisations in problems with heavy advection.Comment: arXiv admin note: text overlap with arXiv:1901.0492

    Scalable angular adaptivity for Boltzmann transport

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    This paper describes an angular adaptivity algorithm for Boltzmann transport applications which for the first time shows evidence of O(n)\mathcal{O}(n) scaling in both runtime and memory usage, where nn is the number of adapted angles. This adaptivity uses Haar wavelets, which perform structured hh-adaptivity built on top of a hierarchical P0_0 FEM discretisation of a 2D angular domain, allowing different anisotropic angular resolution to be applied across space/energy. Fixed angular refinement, along with regular and goal-based error metrics are shown in three example problems taken from neutronics/radiative transfer applications. We use a spatial discretisation designed to use less memory than competing alternatives in general applications and gives us the flexibility to use a matrix-free multgrid method as our iterative method. This relies on scalable matrix-vector products using Fast Wavelet Transforms and allows the use of traditional sweep algorithms if desired

    Novel translational model of resolving inflammation triggered by UV-killed E. coli

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    Whilst numerous studies investigating the aetiology of inflammatory diseases have been performed in rodents, the applicability of these data to human pathophysiology is frequently debated. Regardless of the strengths and weaknesses of rodent models in biomedical research, there is a need to develop models of experimental inflammation in humans. Here, we describe a self-resolving acute inflammatory response triggered by the intradermal injection of UV-killed Escherichia coli into the forearm of healthy volunteers. Cells and exudates were harvested from onset to resolution by applying negative pressure over the inflamed site. Onset was characterized by high blood flow, neutrophilia and peak levels of pro-inflammatory cytokines, whilst resolution showed a decline in blood blow, reduction in neutrophils, increase in monocytes/macrophages and waning of classic pro-inflammatory cytokine levels. An anti-inflammatory effect, defined as suppression of onset phase events, was demonstrated by administering naproxen, a conventional non-steroidal anti-inflammatory drug. In summary, this model of resolving acute inflammation is minimally invasive, highly tractable and allows simultaneous investigation of the vascular response, cellular trafficking and chemical mediator profile of onset and resolution phases of acute inflammation in humans. It can serve as a translational platform to provide mechanistic insights and to test the clinical efficacy of novel anti-inflammatory and pro-resolving drugs, and also as a tool in patients to explore inherent defects in resolution pathways

    Two- and three-body contacts in the unitary Bose gas

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    In many-body systems governed by pairwise contact interactions, a wide range of observables is linked by a single parameter, the two-body contact, which quantifies two-particle correlations. This profound insight has transformed our understanding of strongly interacting Fermi gases. Using Ramsey interferometry, we studied coherent evolution of the resonantly interacting Bose gas, and we show here that it cannot be explained by only pairwise correlations. Our experiments reveal the crucial role of three-body correlations arising from Efimov physics and provide a direct measurement of the associated three-body contact.This work was supported by EPSRC [Grant No. EP/N011759/1], ERC (QBox), ARO and AFOSR. N.N. ac- knowledges support from Trinity College, Cambridge, R.P.S. from the Royal Society and R.L. from the E.U. Marie-Curie program [Grant No. MSCA-IF-2015 704832]

    "Reconceptualising the Consumer Journey in the Digital Age – An Exploratory Study of the United Kingdom Retail Sector"

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    This extended conceptual abstract which describes research that is still in progress provides an analysis of the evolving factors that influence buyer behaviour in the vitally important retail sector. The research originated as a consultancy project concerned with buyer behaviour undertaken on behalf of a specialist Pay Per Click advertising agency in a UK university business school/commercial sector collaboration which then evolved into a research project in its own right
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